Phase II trial (BREAK-2) of the BRAF inhibitor dabrafenib (GSK2118436) in patients with metastatic melanoma

J Clin Oncol. 2013 Sep 10;31(26):3205-11. doi: 10.1200/JCO.2013.49.8691. Epub 2013 Aug 5.


Purpose: Dabrafenib (GSK2118436) is a potent inhibitor of mutated BRAF kinase. Our multicenter, single-arm, phase II study assessed the safety and clinical activity of dabrafenib in BRAF(V600E/K) mutation-positive metastatic melanoma (mut(+) MM).

Patients and methods: Histologically confirmed patients with stage IV BRAF(V600E/K) mut(+) MM received oral dabrafenib 150 mg twice daily until disease progression, death, or unacceptable adverse events (AEs). The primary end point was investigator-assessed overall response rate in BRAF(V600E) mut(+) MM patients. Secondary end points included progression-free survival (PFS) and overall survival (OS). Exploratory objectives included the comparison of BRAF mutation status between tumor-specific circulating cell-free DNA (cfDNA) and tumor tissue, and the evaluation of cfDNA as a predictor of clinical outcome.

Results: Seventy-six patients with BRAF(V600E) and 16 patients with BRAF(V600K) mut(+) MM were enrolled onto the study. In the BRAF(V600E) group, 45 patients (59%) had a confirmed response (95% CI, 48.2 to 70.3), including five patients (7%) with complete responses. Two patients (13%) with BRAF(V600K) mut(+) MM had a confirmed partial response (95% CI, 0 to 28.7). In the BRAF(V600E) and BRAF(V600K) groups, median PFS was 6.3 months and 4.5 months, and median OS was 13.1 months and 12.9 months, respectively. The most common AEs were arthralgia (33%), hyperkeratosis (27%), and pyrexia (24%). Overall, 25 patients (27%) experienced a serious AE and nine patients (10%) had squamous cell carcinoma. Baseline cfDNA levels predicted response rate and PFS in BRAF(V600E) mut(+) MM patients.

Conclusion: Dabrafenib was well tolerated and clinically active in patients with BRAF(V600E/K) mut(+) MM. cfDNA may be a useful prognostic and response marker in future studies.

Publication types

  • Clinical Trial, Phase II
  • Multicenter Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Brain Neoplasms / drug therapy*
  • Brain Neoplasms / mortality
  • Brain Neoplasms / secondary
  • Female
  • Follow-Up Studies
  • Humans
  • Imidazoles / therapeutic use*
  • International Agencies
  • Male
  • Melanoma / drug therapy*
  • Melanoma / mortality
  • Melanoma / pathology
  • Middle Aged
  • Mutation / genetics
  • Oximes / therapeutic use*
  • Prognosis
  • Proto-Oncogene Proteins B-raf / antagonists & inhibitors*
  • Proto-Oncogene Proteins B-raf / genetics
  • Survival Rate
  • Young Adult


  • Imidazoles
  • Oximes
  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf
  • dabrafenib